Various methods for forming microprobes have been taught previously. Some of these methods have involved multi-layer, multi-material electrodeposition to produce microprobes. Examples of such methods are set forth in US Patent Application Publication No. 2011/0132767, by Ming Ting Wu et al., and entitled Multi-Layer, “Multi-Material Fabrication Methods for Producing Micro-Scale and Millimeter-Scale Devices with Enhanced Electrical or Mechanical Properties”.
Some of these methods have involved the use of laser cutting. Example of such methods are set forth in US Patent Application Publication No. 2012/0286816, by January Kister and entitled “PROBES WITH HIGH CURRENT CARRYING CAPABILITY AND LASER MACHINING METHODS”. As exemplified, laser cutting is used to cut out cross-sections of probes from sheets of material such as tungsten, copper-tungsten mixtures, or molybdenum. In the processes, as taught, the sheet material is completely cut through preferably using a plurality of passes of the laser beam such that each pass removes a fraction of the thickness of the sheet. During the cutting the sheet is elevated above a base and once the sheet is cut all the way through individual probes fall away from the sheet. In some embodiments, tip ends and or opposite ends of the probes may be coated with appropriate materials. Such coatings may improve bonding, probe conductivity, and or tip hardness.
Some prior approaches to laser cutting parts from a foil or sheet have included methods of tethering parts to the foil so that they are still minimally attached to the foil following the laser machining process. This modification poses challenges as it still allows movement of the parts in areas that are not tethered, may allow differential heating of various portions of the probes, and requires removal of the tethers without damaging the parts.
A need remains for improved methods for forming microprobes and other microdevices that include materials that are not electrodepositable. A need remains for improved methods of forming microprobes and other microdevices using laser cutting. A need remains for improved methods of forming microdevices and improved microdevices themselves that include both laser cut features and deposited materials.